Regulation in the aeronautical field obliges aircraft operators, such as the airlines, to produce in periodic fashion reliability reports relating to avionic systems. For this purpose, the operators principally have at their disposal three databases for preparing their reliability reports.
A first useable database is that comprising the configuration data of each aircraft. The configuration data of an aircraft correspond to the part numbers of the units of the avionic systems installed in the aircraft.
A second useable database is that relating to the flights of the aircraft. This second database comprises for example data like a date of departure, a departure airport, a date of arrival, a destination airport, a flight duration or a distance traveled.
A third useable database corresponds to that containing the post flight records originating from each aircraft. A post flight record typically contains warning messages and fault messages generated by an aircraft monitoring unit, for example an electronic centralized aircraft monitor or ECAM.
From these databases, the operators typically produce reports including, for a unit, an indicator such as a mean time between unit removal or an average time since installation. These indicators make it possible to obtain an understanding of the performance of a unit relating to its removal. However, when a unit is modified or replaced by another, no method currently allows a possible improvement in performance to be evaluated, for example, a reduction of a failure rate, linked with the modification or replacement of the unit.
It is therefore necessary to propose a solution allowing an evaluation of a rate of change of a failure.